Soil erosion in India

Excessive soil erosion in India combined with consequent high rate of sedimentation in reservoirs and decreased soil fertility has led to grave environmental problems. Soil erosion mostly affects practically all kinds of lands such as the forest lands, agricultural lands, arid and semi-arid lands, surface mines, roads, construction sites, coastal areas etc. Further, since soil formation is a very slow process, the erosion of the upper layer of the soil leaves it barren for a long time, causing grave problems to the agricultural sector.

According to a 2015 report of the Indian Institute of Remote Sensing (IIRS), the estimated amount of soil erosion that occurred in India was 147 million hectares. Under this broad figure, 94 million hectares were claimed by water erosion, 16 million hectares by acidification, 14 Million hectares by flooding and 9 million hectares from wind erosion. 29 percent of the soil that is eroded is lost in the sea while 61 percent is just relocated.

India predominantly witnesses water erosion. The rate of soil erosion by moving water is directly proportional to the intensity and duration of the downpour. In coastal areas the intensity of the erosion is decided by the velocity of the waves, volume of water, extension of vegetation cover, nature of rocks, etc. The southern coasts of India, like the coasts of Kerala are most prone to such kind of aggressive form of Soil erosion. While in the high altitudes of the country glacial, snow and wind action control the nature and intensity of soil erosion. Intense erosion happens in the arid and semi-arid areas where the vegetation cover is scarce. On the other hand, in the northern parts of India, the states of Rajasthan, Haryana, Punjab and Gujarat face the problem of wind erosion. Wind erosion depends on the velocity of the wind, the dryness and the particle size of the surface soil.

The table below shows the state wise area that underwent soil erosion in the year 2013, as recorded by Ministry of Statistics & Programme Implementation, India

State

District

Total degraded area

(In hectare)

Percentage of degraded area

Andhra Pradesh

· Chittor

· Kurnool

· Nellore

127725

309412

169808

·8.56

·17.57

·12.99

Bihar

· Banka

· Bhagalpur

· Gaya

· Munger

· Siwan

29294

32589

7727

144617

22611

·10.51

·12.74

·1.63

·22.79

·10.19

Goa

· North Goa

· South Go

24634

19639

·14.03

·10.09

Gujarat

· Bharuch

· Bhavnagar

· Surat

192841

271337

85469

·24.84

·24.32

·11.01

West Bengal

· North 24 Pargana

· Puruliya

· South 24 Paragna

64062

198619

263635

·16.94

·31.77

·27.29

Manipur

· East Imphal

· West Imphal

10238

15098

·17.71

·29.09

Many studies have been undertaken for understanding the causes that directly lead to the environmental hazard of soil erosion. Natural causes of soil erosion are earthquakes, tsunamis, wave action, droughts, avalanches, volcanic eruptions, landslides, floods, wildfires and tornadoes. The human induced causes of soil erosion include land clearing, improper agricultural practices, deforestation, improper disposal of industrial effluents, over grazing, surface mining, urban sprawl etc. India faces soil erosion from some predominant factors like, land shortage, economic pressure on lands, and decline in the per capita land availability etc.

Soil erosion in our country is a serious threat to both the irrigated and rainfed areas. Every year India loses up to 68 billion rupees according to the National Remote Sensing Agency (NRSA). This cost is calculated with reference to the crop productivity, land use intensity, change in cropping patterns etc.

Soil conservation

It is not enough for an agrarian country like India to apply preventive measures to avoid soil erosion, we also must work towards taking measures to correct soil defects, adequate application of fertilizers and manures, proper irrigation and drainage etc. It’s necessary to maintain the high productivity of the soil.

To conserve soil and avoid soil erosion, preventive measures need to be implemented urgently. Some of these urgent measures include:

Contour tillage: Here the fields are ploughed along the contours and not along the hill slope. This type of plantation is very effective as it leads to the formation of ridges and furrows against the direction of flow and decreases the velocity of water. This type of farming is also profitable as it increases the infiltration of water in the soil, and the plants thus, absorb more water.

Contour bunding: Here first the plants and bushes in the plot of shifting cultivation is cut down. Leaves are slashed down and left on the surface of the soil to get dry. After the decomposition of the leaves and various other plant parts, the dry materials are bundled and arranged in contour lines. The contour line is anchored with pegs, stones, thin branches etc. creating the contour bunds. Once created, the farmers incorporate the remaining decomposed matter in the soil between the bunds and the crop planted. Time takes its course and soil gradually deposits above each bund and is eroded below which leads to formation of rough terraces below. This type of farming is useful for protecting the farmlands which are marginally sloping, hilly and low on productivity.

There are other measures for the conservation of soil like strip cropping, where the crops are grown in strips parallel to each other. Some strips can remain empty and some strips are planted with tree crops, while some are planted with seasonal crops. The tree crops act as wind breakers or shelterbelts to the smaller crops. As various crops are harvested at various time of the year only a few strips of land are left for the soil erosion to harm.

Some other measures to control soil erosion are: construction of check dams, ban on shifting cultivation, controlled grazing, afforestation, mixed cropping and mixed farming etc. Planting species of plants that can restore the ecological balance of an eroded area is also necessary as rehabilitation of the damaged soil is as much important as its prevention from getting eroded.

The Indian government had taken many initiatives to protect the framers and conservation of soil and water during the first (1951-1956) and second five (1956-1961) year plans. A series of soil conservation, research, training centres and demonstration centres were established then to educate the farmers and to initiate the researchers and inventors of agrarian science in the country.

In the year 1962, an initiative of Soil Conservation in the Catchments of River Valley Projects (RVP) was started in India. The scheme thrived to control the premature siltation of reservoirs which in turn enhances the productivity of the catchment areas. Another scheme for flood prone rivers was initiated during the sixth five-year plan (1978–1980). Both the schemes were conjoined together during the ninth five-year plan (1997-2002). These clubbed initiatives catered to 55 catchments that were spread over the space of 27 states of India. During the period of the year 2005-06 an area of 0.17-million-hectare area was treated under this initiative at an amount of 145 crore.

Another scheme, named The Watershed Development Project in Shifting Cultivation Areas ,was initially launched in the North eastern states of India during the eighth five-year plan (1994-95). During the period of its genesis the north-eastern states had spent an amount of Rs. 31.51 crore under the scheme and 0.67 lakh hectare of land was treated. By the time of the ninth five-year plan (1997-2002) 1.57 lakh hectare of land had been benefited from this scheme and the Indian Government had spent Rs 82 crore on it. The revised and latest Watershed Development Project which was revised in the month of November in the year 2000 an amount of Rs.10,000 per hectare will be provided on net treatable area basis. During the tenth five-year plan (2002-2007), an area of 0.89 lakh hectare had been treated which resulted in the expenditure of Rs.88.32 crore.

These and many other schemes by the Indian government have been initiated right after the country became independent but the gap between the implementation from the central and state government seems to be distant from the farmers. The farmers are directly depended on the government for their livelihood and wellbeing. The Government needs to oversee the agricultural produce, supervise its distribution and keep a check on measures necessary to take so that the farmers can survive any calamity be it natural, social or economical in form.